Most Americans are certain Social Security will go bankrupt but are not ready to embrace changes that would shore up the system's finances, according to two surveys by The Washington Post, the Henry J. Kaiser Family Foundation and Harvard University.

Seven in 10 Americans agree with President Bush that Social Security eventually will go bankrupt if Congress fails to act, though most predict that the system will not do so for at least two decades. Yet while Bush has warned of a crisis in Social Security, barely one in four Americans believes that a crisis exists.

More broadly, the polls raise serious doubts about whether Americans are willing to make the choices necessary to fix the system's financial problems. Solid majorities reject both increases in payroll taxes and decreases in retirement benefits, except for the wealthy.

Experts agree that without new revenue coming in or less flowing out as benefits -- or both -- the Social Security system will not be able to pay all its promised benefits, perhaps as early as 2042.

Other recent samplings of public opinion have gauged support for Bush's restructuring plan and other proposals for change, but these polls sought to measure what people knew about Social Security and how misinformation about the program is shaping policy preferences. The polls also tested how subtle changes in the way proposed changes are described can produce major shifts in public opinion.

A majority supports the president's proposal to allow Americans to invest part of their Social Security contributions in stocks or bonds, although opinions on this and other aspects of the president's plan frequently are weakly held and easily moved.

For example, Jerry Traylor, 58, a retired government worker who lives in Newell, Ala., said he supports Bush's proposal for personal accounts, asserting that "a person would have more interest in their own money and their future in retirement if they could invest in stocks."

But like nearly half of those surveyed, Traylor wrongly believed that the costs of creating personal accounts would be negligible. Told that the Bush administration estimates the government initially would have to borrow more than $700 billion to set up such a system, he was incredulous. "That seems very excessive," Traylor said. "I would be less inclined to favor it if it costs that much. That much money could serve a lot of good purposes."

That cost estimate proved to be the most effective of four arguments against Bush's proposal tested in the polls. While 56 percent said they support a plan for individual investment accounts, more than half of those said they would be less likely to do so after hearing the estimate. More than four in 10 supporters wavered when they heard that personal accounts would not, by themselves, reduce the financial problems facing Social Security.

Those opposed to Bush's plan were consistently more resistant to changing their view -- about one in four did -- when confronted with four arguments supporting his proposal.

Taken together, the polls found that the debate over Social Security reflects the sharp divisions of the presidential campaign, and that Bush enters the fight without a clear mandate on the issue. The surveys also found serious misunderstandings about Social Security that could be exploited by either side to shape opinion as the debate evolves.

Americans badly underestimate the share of the federal budget spent on Social Security, and most incorrectly believe that retirees, on average, receive less in benefits than they contributed to the system. And about half of those who support the president's plan incorrectly believe it would protect people from losing retirement money they invested from their personal account.

Perhaps most significant, about seven in 10 Americans believe that the cost of living has been rising faster than wages over the past 20 years, although the reverse is true. This belief probably shapes policy preferences: The same percentage wants to peg initial Social Security benefits to the cost of living, as Bush reportedly wants, instead of the current formula, which pegs them to wage increases. That change would result in significantly lower guaranteed benefits for future generations, according to both supporters and opponents.

Danny Burke, 49, a laid-off maintenance mechanic in Granite City, Ill., who said he struggles to make ends meet, believes based on experience that prices are rising much faster than wages. "Just go to the grocery store and look at a can of corn," he said. "I used to get four for a dollar; now it's five for $2."

But Robert Mitchell, 40, who owns a carpet-cleaning business in Nixa, Mo., correctly said wages rise faster, also based on what he sees. "My parents worked like dogs, and we had one TV and two old cars. Now every person I know has two brand-new cars and a plasma TV," he said.

At the same time, the polls found that the public has quickly become informed on many key elements of the Bush plan to create individual investment accounts.

Most already know that Bush's changes would exempt those 55 and older, and people polled understand that the accounts would be protected from use by government. They also know the plan would limit investments to a few relatively safe stock and bond funds.

To measure knowledge about Social Security and the Bush plan, The Post, the Kaiser Family Foundation and Harvard conducted two national telephone surveys. The first poll of 1,236 randomly selected adults was conducted Feb. 3 to 6 and measured what people knew about Social Security and their attitudes toward restructuring.

The second survey, of 1,231 randomly selected adults conducted Feb. 4 to 6, focused on what people initially have learned about the Bush plan. Both surveys have margins of sampling error of plus or minus three percentage points.

The polls suggest that the debate over Social Security restructuring is a battle of words -- but not necessarily the words the administration has worried about.

Americans seem not to change their views when the president's plan is characterized as a "private" rather than a "personal" investment account -- a change from earlier studies, in which the use of "private accounts" or "privatization" drove down support. Either way, a modest majority favored the proposal, the survey found.

Far more sensitive was the characterization of the way a restructuring would include a provision to recalculate initial benefits for retirees. Opposition rose from 68 percent when this change was characterized as "reducing the rate of growth in benefits" to 86 percent when described as "cutting guaranteed benefits." Both phrases accurately describe what would happen.

The polls also revealed that the fault lines of the presidential campaign are resurfacing in the Social Security debate. Those surveyed split down the middle on whether they trusted Democrats or Republicans to lead on Social Security. And they were almost equally divided on the values that lie at the heart of the current debate -- self-reliance vs. the government's obligation to protect its citizens.

Half said the overriding value is having a guaranteed minimum standard of living in retirement, even if that means the government decides how all Social Security taxes are invested. Nearly as many said the system should above all allow Americans to invest a portion of Social Security taxes as they wish, even if they end up taking risks that hurt them financially.

Six in 10 Democrats valued the guaranteed standard of living, while six in 10 Republicans valued the freedom to invest on their own. Seniors valued the minimum standard of living by 57 percent to 32 percent. Those younger than 40 valued the right to invest on their own by 53 percent to 42 percent.

Attitudes of those older than 55 often differed significantly from those of younger Americans, with strikingly little variation among those 18 to 55. For example, people younger than 55 are about twice as likely to say the system is in crisis than older adults. They are twice as likely as older people to say they expect to receive less in Social Security benefits than they paid into the system.

"I'm expecting to live on my own savings. I'm going to prepare for the worst so I don't get in trouble," said Sarah Kirby, 19, a political science and history major at Marquette University who said she believes Social Security is "outdated" because it did not anticipate the longevity of today's seniors.

Benjamin Palmer, 23, general manager of a Pizza Hut in New Brighton, Pa., also said he expects Social Security to run out before he retires. "Who cares?" Palmer said of the risk involved in stock investments. "People my age have no guarantee now that Social Security will be there for us. So it would be more than we've got now."

Stephen Davis, 55, a metal fabricator who lives in Forney, Tex., disagrees with Bush's proposal, even though he voted for him.

"I think it's dangerous, because in the stock market the amount of risk involved is just too great," Davis said. "It's kind of like, let the fleecing begin, benefiting stock insiders, stockbrokers, large corporations."

The survey also suggests that Bush begins the fight over Social Security without a majority of Americans backing him. One in five wants him to lead the way on Social Security, while a similar proportion has more confidence in congressional Republicans. More than four in 10 -- 43 percent -- say they trust congressional Democrats on the issue. Taken together, the findings suggest that about half want Democrats to handle this issue, while about half have more confidence in Republicans.

Although half of all retirees say Social Security is their major source of income, few younger Americans say they plan to rely on the system to be anything more than a supplement to their retirement incomes.

More than two-thirds of the country knows that payroll taxes paid into the Social Security trust fund are lent to the federal government and spent on other programs. But more than six in 10 of these doubt that the federal government will ever pay that money back -- one big reason the system is now in trouble, a lopsided majority says.

"Pay it back? The government?" said Margaret Abrams, 59, who owns a plumbing company in Somerville, Mass. "They're never going to pay it back. It's not on the list."